A majority of British voters chose to leave the EU in a referendum held Thursday.

Results Friday showed 52 percent of voters chose to leave, while 48 percent chose to remain. The majority of voters in Scotland, Northern Ireland and London opted to stay, while the rest of England largely voted to exit.

The U.K., which has been in the EU for 43 years, will now enter a two-year negotiation with the EU on how it will leave.

In the aftermath of the vote, financial markets around the world were reeling. The Dow plunged 500 points on Friday morning.

British Prime Minister David Cameron, who had backed the Remain campaign, held a somber press conference outside 10 Downing Street to announce that he will step down by October.

"The British people have voted to leave the European Union and their will must be respected," he said, as his tearful wife, Samantha, stood nearby.

He continued: "I will do everything I can as Prime Minister to steady the ship over the coming weeks and months but I do not think it would be right for me to try to be the captain that steers our country to its next destination."

The newly elected London mayor, Sadiq Khan, also told the nearly one million Europeans living in the city that despite the vote, they are "very welcome here."

"As a city, we are grateful for the enormous contribution you make, and that will not change as a result of this referendum," he said.

"People are angry, all over the world, they're angry," he told reporters in Turnberry. "They're angry over borders, they're angry over people coming into the country and taking over. Nobody even knows who they are. They're angry about many, many things."

When asked if that applied to the U.S., he responded: "There's plenty of other places. This will not be the last."

In a statement released Friday, Trump said that soon it will be America's turn to vote.

"The people of the United Kingdom have exercised the sacred right of all free peoples," he said. "They have declared their independence from the European Union... Come November, the American people will have the chance to re-declare their independence."

Hillary Clinton also commented on the result Friday, saying it underscores the importance of November's election.

"This time of uncertainty only underscores the need for calm, steady, experienced leadership in the White House to protect Americans' pocketbooks and livelihoods, to support our friends and allies, to stand up to our adversaries, and to defend our interests," she said in a statement. "It also underscores the need for us to pull together to solve our challenges as a country, not tear each other down."